Air freshener dispensers are often used in public washrooms to control odor in the enclosed area. Although air fresheners are sometimes referred to as scented or unscented, in reality all air fresheners give off a fragrance, and it is simply a matter of degree as to whether the air freshener is perceived as having its own scent or merely masking the undesirable odor in the washroom.
Air fresheners may be dispensed continuously, at regular intervals, or in response to a particular event, such as when the light in the washroom is turned on. The air freshener is typically dispensed from a source of fragrance through evaporation or atomization. The air freshener dispenser is usually located high on the washroom wall where suitable air flow exists to accelerate the dispensing of the air freshener. This location has the further advantage of preventing atomized air freshener from being sprayed directly on people using the washroom. Unfortunately, when the air freshener is dispensed in high places it tends to rise to the ceiling where it can be suctioned from the washroom via the ventilation system before it can control odor.
Due to its awkward location, maintenance personnel are sometimes unable to detect when the air freshener needs to be replaced. Furthermore, the placement of air freshener high on the wall requires maintenance personnel to stand on a ladder or platform in order to service it. While some air freshener dispensers have a beeping noise or blinking light to indicate that the supply of air freshener needs to be replaced, even with these replacement reminders, air freshener dispensers are frequently not maintained on a regular basis due to the inconvenience of maintaining the air freshener.